Machine tool transmission and control therefor



March 2, 1954 R. H. scHuMAN 2,670,632

MACHINE TOOL TRANSMISSION AND CONTROL THEREFOR Filed oct. 1e. 1951 esheds-sheet 1 R. H. SCHUMAN March 2, 1954 MACHINE TOOL TRANSMISSION ANDCONTROL THEREFOR Filed 0011. 16, 1951 6 Sheets-Sheet 2 March 2, 1954 R.H. scHuMAN MACHINE TOOL TRANSMISSION AND CONTROL THEREFOR Filed 001'..16. 1951 6 Sheets-Shea?I 3 INVENTOR PAL PH H. 5cm/MAN BYW' @Mui Arron/v5ya .it t

R. H. SCHUMAN March 2, 1954 MACHINE ToorJ TRANSMISSION AND CONTROLTHEREFOR Filed Oct. 16, 1951 Sheets-Sheet 4 INVENTOR. ,9m PH Jef/mmv m,ff

March 2, 1954 R. H. scHuMAN MACHINE TOOL TRANSMISSION AND CONTROL.THEREFOR Filed Oct. 16. 1951 6 Sheets-Sheet 5 R. m n W.

QQLPH H JCHU/vm/v ATToe/VEJJ March 2, 1954 R. H. scHuMAN 2,670,632

MACHINE Tool.l TRANSMISSION AND CONTROL THEREFOR Filed Oct. 16, 1951 6Sheets-Sheet 6 INVEN TOR. ,PAL PH /71 Jc/fu/xm/v A Bwaamwyw Arme/Veys YPatented Mar. 2, 1954 MACHINE TOOL TRANSMISSION AND CONTROL THEREFIORRalph H. Schuman, Cleveland, Ohio, assignor to The Warner & SwaseyCompany, Cleveland, Ohio, a corporation of Ohio Application October 16,1951, Serial No. 251,549

27 Claims.

This invention relates to a machine tool, and more particularly, to animproved mechanism for controlling the speeds, direction of rotation andthe starting and stopping of a movable part, for example, the workspindle of a machine tool.

A machine tool provided with a change speed transmission for a movingpart thereof and having a means for preselecting the direction and speedof movement of that part for each dierent operative step of a workcycle, which preselected movement is thereafter initiated by action of asingle lever, is disclosed and claimed in United States Letters PatentNo. 2,501,286, issued March 2l, 1950 to C. M. Mirossay. The principalobject of this invention is to provide a machine tool with atransmission and control therefor of the general type disclosed in thatpatent and with a means responsive to a predetermined torquedifferential between the input and output shafts of the transmission toautomatically control the shifting thereof for providing the preselectedspeed and direction of movement of the movable part for a given step ofa work cycle, whereby wear and tear on the gears is reduced bypreventing clashing thereof and the eiiiciency of the machine tool isimproved by enabling the shifting of the gears to always occur at theearliest proper time thereby reducing the time lost in making suchshifts so that the productive capacity of the machine is improved.

Another obejct of the invention is to provide an improved machine toolhaving a geared change speed transmission with an improved means tocontrol the shifting of the gears thereof such that a desired speed anddirection of movement for a moving part during the next operation of awork cycle can be preselected while the part is engaged in the prioroperation, shifting to the preselected speed and direction of movementbeing prevented until the torques of the input and output of thetransmission are in proper relavide an improved machine toolandtransmission therefor as dened above and in which a desired directionand rate of movement of a movable part of the machine tool may bepreselected While vthe said part is moving at a different rate and/or ina different direction and shifting to the preselected rate and directionof movement is initiated by imparting a crawl or non-working speed tothe output of the transmission, the shifting being automatically eiectedwhen the input and output of the transmission have attained the propertorque relationship.

A still further object of the invention is to provide in a machine toolmeans for automatically shifting the shiftable elements of a changespeed transmission thereof once the shifting cycle has been manuallyinitiated, the mechanism being such that the completion of the shiftingcycle is automatically attained independently of any eifort or attentionon the part of the operator and only when the torque of said outputshaft is in predetermined relationship to the torque of the input shaftso that shifting is eected without clashing or damage to the shiftableelements.

The invention further resides in novel features of the construction andin the combination and arrangement of the parts of the apparatus, andfurther objects and advantages of the invention will be apparent tothose skilled in the art to which it pertains from the followingdescription of the present preferred embodiment thereof which isdescribed with reference to the accompanying drawings, having identicalparts in the several views designated by the same reference characters,and in which:

Fig. 1 is a front elevational view of a turret lathe embodying theinvention;

Figs. 2A and 2B, when joined along the broken line A B, comprise adeveloped view of the novel change speed transmission in the headstockand which forms the drive to the Work spindle of the lathe shown in Fig.1, certain parts being broken away and others shown in section to moreclearly illustrate the invention;

Fig. 3 is a view, partly in section and partly in end elevation, of atorque responsive member and associated valve, the view being takensubstantially on the line 3 3 of Fig. 2A and looking in the direction ofthe arrows;

Fig. 4. is an enlarged sectional view taken substantially on the line 44 of Fig. 3 and looking in the direction of the arrows;

Fig. 5 is a sectional view taken substantially on the line 5 5 of Fig. 4and looking in the direction of the arrows;

Fig. 6 is an enlarged, fragmentary viewof a vportion of Fig. eillustrating the manner in which va tortuous passageway is provided toeffect a time delay by ow restriction;

Fig. '7 is a sectional view through the torque 3 differential responsivemeans of this invention, the view being taken substantially on the line1--1 of Fig. 2A as seen when looking in the direction indicated by thearrows;

Fig. 8 is a fragmentary elevational view of a portion of the torquedierential means of Fig. '7, illustrating the cam surfaces thereof;

Fig. 9 is a fragmentary elevational View, to an enlarged scale, of aportion of the headstock of the turret lathe shown in Fig. l andillustrating the main control lever and valve controlled Ythereby;

Fig. 10 is a sectional View taken substantially on line IIJ-I of Fig. 9,looking in the direction of the arrows, and shows, in full lines, themain control lever and its valve in the position for initiating a gearshift;

Fig. 11 is a sectional View taken substantially on the line ll-ll ofFig. and looking in the direction of the arrows;

l2 is va detached view of .a portion -of the headstock, .the view beingprincipally in end elevation but with parts broken away and -others insection, to show the preselector valve and its actuator;

Fig. 13 is a fragmentary :sectional View taken substantially on the line|3-3 of Fig. 12 and viewed in the direction indicated by the arrows;

Fig. 14 is a sectional view through the preselector valve with a portionof the supporting member therefor shown in elevation, the section beingtaken substantially on the line tal-ld of Fig. 13 and viewed in thedirection indicated by the arrows;

Fig. 15 is a detached plan vie-w of the preselector valve shown in Figs.12, 13 and 14 with a portion of Vthe housing broken away to show a checkvalve therein;

Fig. .116 is va developed view of the periphery of the preselector valveshown in Figs. 12 to l5 illustrating the interconnections of certainpassages therein;

Fig. 17 is a fragmentary sectional view through the inching valve of theapparatus, the view being taken substantially on the line I'l-I'I ofFig. 9 and viewed in the direction indicated by the arrows;

Fig. 18 is a somewhat schematic view of the fluid pressure circuit inthe headstock of the machine with the inching valve shown in bothelevationV and section to more clearly illustrate the fluid passageways;Iand Fig. 19 is a view similar to Fig. l0, but to a smaller scale andshowing the main vcontrol valve in its'intermediate or normal positioncorresponding to the position thereof in'ig. 18.

The invention is here illustrated as embodied in a .turret lathe which,as shown in Fig. 1, comprises a fbed having a heads'tock 26 at one endthereof. Slidable upon the bed are the usual 'turret saddle 21, with itsslide 28 ,and turret 29, and a cross slide carriage 3i! provided withcross slide 3|. These portions of the lathe are conventional and henceneed not be described in detail.

The headstock `2t of the lathe has a work spindle 32 journalled therein,see Fig. 2B, for rotation in either direction at a plurality ofdifferent speeds. For this purpose, the headstock is provided With achange speed transmission comprising an input shaft 33, Fig. 2A, whichis driven from a power source, not shown. This shaft is selectivelyconnectible with the spindle 32 by means of a plurality of clutches andshiftable elements of the transmissionn the shiftable elements carryinggears which selectively intermesh to provide the diiferent speeds of thespindle. The shifting of the gears, operation of the clutches, andoperation of a brake of the transmission are all eifected by iluidpressure operated actuators as will hereinafter become apparent.

The input shaft 33 of the *transmission is journalled by means ofsuitable bearings 34 and 35 vin a Wall 36 of the headstock 26 and by abearing 3l' .in an inner Wall or web 38 of the headstock. Intermediatethe bearings 35 and 31, the shaft 33 has gears 39 and 40 secured theretoin spaced relationship. The gear 39 is continuously in mesh with a gear4I which is connected to a clutch member l2 rotatably supported upon acountershaft 43 that s suitably rotatably journalled in the walls 35 and38. The gear 49 is continuously in mesh with a gear 44 rotatablysupported on a jack shaft 45 mounted in the wall 38 and a bracket or-wa'll 5. The gear 44 .has a relatively wide .face and is also incontinuous mesh with a gear 1H secured to .a clutch vmember 43 rotatablymounted upon the .shaft 43.

The clutch member 42 is part Iof `a mai-n tor- Ward clutch, generally`designated 49., vwhich is adapted to control rotation of the spindle3-2 in the forward direction :at any -of its speeds. The clutch member48 is a portion of the main 'reverse clutch, generally designated 50,and which .is adapted to connect the input shaft 33 through thetransmission to the spindle 3.2 for rotation of the latter in thereverse direction a-t any selected speed. The clutches 49 and 5B are fofthe friction plate type and are actuated, as hereinafter described, toselectively connect either the member v42' 'or the member 4B 4with thesha-ft 43. Thus, the clutch 4B has a plurality of spaced annularfrictional members 51 keyed for rotation ywith the member 42 :andfitting fbetween annular members -52 which are :keyed for rotation witha sleeve V53 that is in 4turn keyed with the shaft t3. Likewise, theclutch 511 comprises similar -sets of annular members cooperatingrespectivelyfwith 'the clutch member 4B and the sleeve .member 5t. Theconstruction is such that when an :axial thrust is exerted on theannular friction members, such as 51 and 52, they `are forced intofrictional engagement so as to .clutch `the correspond-ing gear 4l or 4lwith fthe shaft 43 and thereby rotate the latter in either the forwardor reverse direction depending upon whether t is clutch le or vclutch5l! which is operated.

`The clutches 49 and 50 :are adapted to be fluid pressure actuated andfor this purpose the sleeve member 53 has a radial flange portion 54intermediate its ends and an outer `axially extending `wall 55 providingtwo annular cylinders one yeach on either side cf the radial wall 54,see Fig. 2A. Within one of these annular cylinders is slidably disposedan annular piston 5G which is adapted to engage and exert an axialthrust on the fric- .tion members ofthe forward clutch 49. The otherannular cylinder or chamber has an annu.- `lar piston 51 slidabletherein and adapted to exert an axial thrust on the friction members ofthe clutch 5B. Fluid under pressure is selectively supplied behind thepistons 56 and 5l under control of the mechanism as hereinafterdescribed. For the present it is sufcient to note that the space betweenthe piston 56 and the wall 54 communicates through a passageway 58, inthe sleeve -{SIL-and a radial passageway 59 in the shaft-.13 with a bore6B extending axially throughvthe sha-ft 43.-

bore 5l) is connected by a radial b01`e-6l adjacent the right-hand endthereof as viewed in Fig. 2A, with an annular groove or chamber 62inthebushing or bearing A63, the groove 62 in turn communicating with apassageway 34 extending from the bushing and connected by means of apipe or conduit to the main control Valve, as hereinafter described.

A hollow pipe or tube 65 is provided within the bore 60 of the shaft 43and this pipe or tube 65 has fluid-tight packings or collars 66 and 51adjacent either end thereof to prevent passage of uid thereabout. Thecollar 66 is intermediate the radial passageway 59 in the shaft 43 andan adjacent radial passageway 68, the latter being in communication withthe region at the rear of the piston 51 through a passageway 59 in thesleeve 53. The collar 61 is intermediate the radial passageway 6| and asimilar radial passageway 10 in the shaft 43, which passageway 10communicates, through an annular groove or chamber 1| and a passagewaysuch as 12, with a pipe or conduit for uid under pressure and controlledas hereinafter described. The outer end of the bore 60 in the shaft 43is closed by a plug 13.

It will be apparent from the construction just described that, whenfluid under pressure is supplied to the passageway S4, this pressureduid will act through the passageway 6|, groove 62, bore 60 andpassageways 59 and 59 to move the piston 55 to the left as viewed inFig. 2A, thus effecting engagement of the friction members of the clutch49. This fluid pressure cannot act upon the piston 51 since it isblocked by the collars 66 and 51. When, however, fluid under pressure issupplied to the passageway 12, this pressured fluid is effective throughthe passageway 10Yand groove 1|, the interior of the pipe 65, and thepassageways 98 and 99 to force the piston 51 to the right as viewed inFig. 2A thus effecting engagement of the friction members of the clutch50.

In addition to the two clutches carried by the shaft 43 the latter isalso provided with a fluid pressure operated brake, generally designated13, see Fig. 18. This brake is constructed similar to the clutches 49and 59 in that it comprises spaced annular friction members 14 whichare, however, held from rotation by being keyed to a bushing or housing15 for the end of the shaft 43. Annular members 16 are interposedbetween the members 14 and are connected for rotation with the shaft 43by means of a sleeve 11 connected with the latter. Braking action uponthe shaft 43 is effected by exerting an axial thrust on the annularmembers 14 and 19 by means of an annular flange 18 provided on a piston19 slidably supported in a cylinder 80 which is in axial alignment withthe end of the shaft 43, see Fig. 18. Fluid under pressure is conductedto the cylinder 80 at a point behind the piston 19, by means of suitablepipes or conduits connected to a passageway 8| in the wall of thecylinder 80.

Adjacent the clutch 49, the shaft 43 has gears 82 and 83 secured theretofor rotation therewith. The gear 82 is of smaller diameter than the gear83 and these gears are adapted to respectively cooperate with gears 84and 85 which are connected for rotation together and for axial slidingmovement on a countershaft 86 by virtue of a splined connectiontherebetween. As shown in Fig. 2A, the gear 82 is in' mesh with the gear84 to thereby effect rotation of the shaft 86 when either the clutch 49or 50 is engaged thereby pro- -viding one speed relationship of theshafts 43 and 86 in either direction of rotation.y A second speedrelationship between the shafts 43 and 86 is provided by axiallyshifting gears 84 and 85 to the right as viewed in Fig. 2A thusdisengaging the gear 84 from the gear 82 and meshing the gear with thegear 83. This sliding of the gears 84 and 85 is effected by means of ashiftable member or element 81, see Fig. 18, which is connected by apiston rod 88 to a piston 89 adapted to be moved by fluid under pressureas hereinafter described. The member 81 engages in an annular groove 90in the common mounting member 9| for the gears 84 and 85.

It will be apparent therefore, that when fluid under pressure is appliedat one side of the piston 89 the latter will move to the position shownin Fig. 18, thus engaging gears 82 and 94. When fluid under pressure isapplied at the other side of the piston 89, however, the latter shiftsto the right, as viewed in the drawings, thus causing the shiftablemember or element 81 to move the gears 84 and 85 from their position asshown in Fig. 2A so that the gear 85 is now engaged with the gear 83 andthe gears 82 and 84 are disengaged.

Also slidably splined to the shaft 86 is a pair of integral gears 92 and93 which are adapted to respectively mesh with gears 94 and 95Yconnectedto a countershaft 96 which is journalled in the walls 36 and 38 of theheadstock, see Fig. 2B. The gears 92 and 93 may be shifted from theirpositions as shown in Fig. 2A to effect meshing of gear 93 with gear 95by means of a shiftable element or member 91, see Fig. 18, which has aportion straddling a part of the periphery of the gear 92 to effectaxial movement of the gears 92 and 93, the member 91 being connected bya piston rod 96 with a piston 99 in a cylinder to which iluid underpressure may be supplied at either side of the piston as will behereinafter readily apparent.

It will be evident therefore that for each position of the gears 84 and85, the shaft 96 can have either of two different speeds in eitherdirection, depending upon the position of gears 92 and 93 and which ofthe clutches 49 and 59 is energized. There are, therefore, provided fourdifferent speeds of the shaft 96 with respect to the speed of the inputshaft 33.

In` addition to the gears 94 and 95, shaft 96 is also provided with agear |00 which i-s connected withfthe shaft 99 for rotation therewithand is adapted to be selectively engaged or disengaged by a gear |0|which is slidably splined on a countershaft |02. The gear |0| isconnected to, or integral with, a smaller diameter gear |03 which isalso splined to the shaft I 02 and adapted to selectively mesh with thegear 94. Thegears 0| and |03 are moved axially of the shaft |02 toeffect the above-mentioned selective engagement of the gearsv |00, |0Ior gears 94, |03 by means of a suitable shiftable element or member |04which has a portion engaged in an annular groove or recess |05 of anattached or integral boss |08 for the gears |0| and |93. The member |04is connected by a piston rod |91 to a piston |08 in a cylinder adaptedto receive fluid under pressure at either side of the piston forshifting of the gears |0| and |03.

It will be apparent, therefore, that for each speed of the shaft 99,there are two speeds of the shaft |02 in either directio'nnd hence thereare eight speeds of the shaft |82 for a given speed of the input shaft33 or of the intermediate shaft 43.

The shaft |02. also has a second pair of gears |09 and ||0 splinedthereon which gears areA either integral or connected for rotationtogether and for sliding movement on the shaft |02, the gear |09 beinglarger than the gear I0. The gear |09 is adapted to mesh with a, gear II connected with the spindle 32. while the gear is adapted to mesh withthe gear |2 also connected with spindle 32. It will be evident,therefore, that there are two possible speeds of the spindle 32 for eachspeed of the shaft |02 and hence there are sixteen speeds of the spindle32 for each speed of the input shaft 33 or of the intermediate shaft 43in either direction of rotation of the shaft 43.

In order to eifect theaforementioned shifting ofthe gears |09, |'|0, thelatter are provided with a boss I I3 having an annular groove or recessI I4 in which is engaged a suitable shiftable element or member I5connected by a, piston rod I |6 with piston The piston ||1 is, like thepistons 83, 59 and |08. adapted to be moved in either direction by theapplication of fluid under pressure to either side thereof.

The gear sluiting rods 88, 38, |01 and IIE are slidably guided within abracket or wall I i8 provided in the headstock and the pistons 8S, 99,|08 and ||1, respectively, are received in cylinders IIS, |20, |2|, |22,also provided in the headstock. The portions of the cylinders to theleft of the pistons, as viewed in Fig. 18, are interconnected bypassageways |23, |24 and |25 while uid may ybe admitted on the otherside of the pistons through the passageways |261, |21, |28 and |29,therebyk controlling the selective shifting of the gears of thetransmission.

The operation of the gear shifting fluid pressure motors, comprising theaforementioned pistons 8S, 99, |08, IIT and cylinders IIS, |20, |2|, |22is selected by a speed selector valve, generally designated |30, whichis mounted in the headstock and comprises a valve housing in which thevalve body I 3| is rotatably mounted, see Figs. 12, 14 and 18. The valvebody |3| is provided with a plurality of passageways for selectivelyinterconnecting the several ports of the valve housing in accordancewith the rotative position of the valve. In order to eiect the desiredrotation of the valve, the valve body 3| is coupled to a shaft |32 whichextends outwardly of the valve housing and is in turn coupled with ashaft |33 rotatably U supported in the upperv part of the headstock 26and extending beyond the front thereof where it is provided with a handwheel |34, see Figs. l and l2.

In order to exactly locate the valve body |3| in each of its diierentpositions and to retain the valve body in any such position againstaccidental displacement, the shaft |33 has a disk |35 fixed theretowhich disk has its periphery provided with sixteen recesses orserrations each corresponding to lone of the sixteen vpossible speeds ofthe spindle. Cooperating with the disk |35 is a roller |36 carried atthe lower end of the pivoted arm E31 which is urged towards thecircumference of the disk |35 'by a spring pressed plunger |30, see Fig.13. It will thus -be seen that the roller |36, arm |31 and plunger |38cooperate with the disk |35 to provide a spring detent means forretaining the selector valve |30 in a selected position. The detent doesnot, however, prevent turning of thevalverby the hand wheel |34 when a.diilerent speed of the spindle is-to be selected ashereinafter-described.- Y'

The shaft |33 of the selector valve also has a bevel gear 39 fixedthereto which meshes with a bevel gear |40 xed to the lower end of anindicator shaft |41 carried by the headstock. The shaft 54| carries asuitable drum or other indicator |41 movable relative to calibrations onthe headstock for showing the cutting speeds in feet per minute forvarious types of work, thus enabling the operator to select the properposition of the valve |30 and hence select the proper speed of thespindle by simply turning the hand wheel |34 until the indicator |42 isat the calibration indicative of the work to be performed. The detailsof this indicating means do not form a part of this invention and hencewill not be further described.

Supported adjacent the selector valve |30 is an interlock time delayvalve, generally designated |43. In the illustrated embodiment, the timedelay valve |43 is provided in the same housing as the selector valve|30, thereby facilitating assembly and maintenance of the parts. Thetime delay valve |43 comprises a, valve chamber |44 in which is slidablymounted a valve body |45 having a pair of spaced lands |4|v and |41. Thevalve body |45 at one end thereof has a reduced diameter extension |48slidably received in a bore provided in the adjacent end wall |49 of thevalve chamber, this bore being connected with a conduit |50 for apurpose hereinafter described. The other end of the valve chamber |44 isprovided with a iluid flow restricting unit |5I, which unit comprises aseries of baille disks with peripheral notches and projections onalternate disks and staggered with respect to each other therebyproviding a tortuous path therethrough for the pressure fluid so that apredetermined interval of time is required for the :duid to flow throughthe unit |5| and into the portion of the valve chamber adjacent the land|46.' The details of a time delay device of this nature are fullydisclosed in the aforementioned patent to Mirossay 2,501,286, and henceare not here repeated.

The main control valve means for the apparatus, generally designated|52, is carried by a plate |53, bolted or otherwise secured to the frontof the headstock 26, see Figs. 10 and 19. The housing |54 of this maincontrol valve extends rearwardly through an opening in the front Wall ofthe headstock 26, and is provided with a valve chamber in which a valvebody |55 is rockably mounted. The valve body |55 is, in turn, providedwith a valve chamber in which a gear shifting cycle control valve body|53 is slidable. The rockable valve body |55 has a reduced diameterhub-like portion extending outwardly of the valve housing and plate |53and is rotatably supported in the. latter. The slidable cycle valve body|56 has an elongated extension passing through the hub portion of thevalve body |55 and is adapted tc extend, outwardly slightly beyond thehub portion, see Fig. 19.

A handle bracket |51 is keyed to the outer end of the hub portion of thevalve body |55 and this bracket has two spaced outwardly extending lugsor ears |53 which support a transversely extending rod |59 on which ahandle body |60 is rockably supported. The handle body |60 has a handle|6| at its upper end for manipulation of the body and the valve bodies|55 and |55 as hereinafter described. lThe handle body |60 also carriesa stop member or plate |02 which has two spaced downwardly extendinglugs disposed on either side of a forwardly projecting stop member orlug |63 whichv is bolted or otherwise secured to the plate |53, thusdening the maximum rocking movement in opposite directions 9 of thehandle body |60 when the latter is in eitherits Clutches Locked or GearShifting" positions designated I and III, respectively, in Fig. 19. Theproportions of the stop members |62 and |63 are such, however, that whenthe handle |6| and the handle body member |66 are rocked outwardly, thatis, counterclockwise as viewed in the drawings, to its maximum position,designated II r Free to Shift in Fig. 19, the stop member |62 will clearthe stop member |63 and permit rotation of the handle |6| and the valvebody |55.

The handle body |60 is provided below the rod |59 with a spring pressedplunger |64 which cooperates with the lower end of the handle bracket|51, see Figs. l0 and 19 to normally maintain the handle in the positiondesignated I and which corresponds to the Clutches Locked position. Whenthe handle is rocked inwardly, to the position III, and which is theposition of the handle shown in solid lines in Fig. 10, the plunger |64is out of contact with the handle bracket |51 and the handle is retainedin this position by a spring detent until automatically returned toposition I as hereinafter explained. When the handle is rocked toposition II, that is, to its outermost position as shown in Fig. 19, theplunger |64 is depressed and functions when the handle is released torestore the latter to position I.

The handle body |66 is provided, above the pivot rod |59, with anabutment |65 which may be formed integral on the body or as a separatepin. This abutment is aligned with the extension of the shiftable cyclecontrol valve body |56 and acts when the handle |6| is moved to positionIII to move the slidable valve body |56 inwardly. As will be hereinafterdescribed, fluid pressure acts on the inner end of the slidable valvebody |56 at the end of a gear shifting cycle to move the said bodyoutwardly, thus automatically restoring the handle |6| from position IIIto its normal position I. This outward movement of the slide valve bodyis assisted by a spring |66 acting thereon, the slide valve beingretained against accidental displacement while in either of its twopositions by a spring detent |61 cooperating with spaced grooves orrecesses |68 on the valve body |56.

As noted above, the cooperating stops |62 and |63 provide for onlylimited rocking movement of the handle |66, |6| when they are in eitherposition I or position III. This extent of rocking movement issufficient to move the handle only between neutral and brake positionswhich are designated in Figs. 9 and 18 as N and 13, respectively. Thehandle |6| cannot be rocked to either the position marked F or thatmarked Rj and which correspond respectively with forward and reverserotation of the spindle, when the handle is in either the I or IIIpositions. However, the handle 6| may be rocked outwardly to the IIposition, against the force of the spring plunger |64, thus disengagingthe stops |62 and |63 so that the handle may then be rocked t either theforward or reverse positions, F or R, respectively. When the handle isreleased the plunger |64 will return it from position II to position I,where the stop members |62 and |63 will again prevent rocking movementof the handle until it is Vagain moved outwardly to the position II.Suitable means may be provided to assist in determining each of the fourrotative positions, E N, B and R, 0f the handle |6| and to retain thelatter against accidental displacement therefrom. As illustrated in Fig.9

of the drawings, this means comprises a spring detent |69 whichcooperates sequentially with spaced notches or recesses on the valvebody |55 to properly position and retain the latter and the handle |6|in a selected rotative position. If desired, positive stops may also beprovided to limit the maximum rocking movement of the valve handle |6|as is disclosed in the aforementioned Patent 2,501,286.

In accordance with this invention, a desired speed of the work spindle32 is selected by positioning the selector valve |39 and the necessaryshifting of the gears to provide the selected speed is initiated byactuation of the main control valve means |52 through rocking the latterinwardly to its position III. However, the actual shifting of the gearscannot occur until the torques of the input shaft 33 and the outputshaft, such as shaft |62 or the spindle 32, are in proper relationshipto prevent undue strains on the mechanism or clashing of the gears. Thiscontrol of the gear shifting is effected by a torque responsivegoverning valve |16 operating in response to the torque differentialbetween the input and output of the transmission to control theapplication of pressured fluid to the gear shifting fluid motors.

As shown in Fig. 2B, the illustrated embodiment of the invention has theshaft 96 extended beyond the gears et and 95 and this extended portionis provided with a fluid pressure operated clutch |1| for selectivelyconnecting a gear |12 to the shaft 66 for rotation therewith. The clutch|1| comprises a sleeve |13 which is keyed to the shaft 96 and has aplurality of spaced friction members |14 keyed thereto. Alternating withthe friction members |14 are spaced friction members |15 keyed to anannular clutch member |16, journalled on the sleeve |13. The gear |12 isconnected to the clutch member |16 for rotation therewith and hence thegear |12 is operatively connected to shaft 96 when the latter isclutched to the member |16 through operation of the friction members |14and |15. The friction members are thus moved into operative relationshipby means of an annular piston |11 slidable in an annular cylindersurrounding the sleeve |13. The rear face of piston |11 is recessed toprovide for admission of pressured fluid therebehind through passageway|18 in sleeve |13 which communicates with passageways |19, |86 and |8|in the shaft 96. The pressured fluid is conducted to the passageways inshaft 96 by suitable conduits, as hereinafter described, connected witha stationary sleeve member |62 which surrounds the shaft 96 and has anannular passageway |63 communicating with the passageway |8| in theshaft.

The gear |12 is in continuous mesh with a gear |64 which is integralwith or connected to a gear |86 provided on a countershaft |66. The gearis in continuous mesh with a gear |81 formed integrally on a tubularmember |66 of a torque responsive mechanism, generally designated |89.Keyed to one end of the member |86 is a rst camming member |96 of thetorque responsive mechanism, which member has a plurality of camsurfaces |9| on a radial face thereof. The member |90 is thereforedriven from the shaft 96 when clutch |1| is engaged and, since shaft S6is geared with shaft |62 and spindle 32, the torque exerted on member|99 is directly related to the torque of the output of the transmission.

The shaft 33 is extended beyond the gear 40 and the bearing 31 and thisextended portion of the shaft has a small diameter gear |92 fixedtheretiio rvintegralI threvvith. Thegear v|92 is inrcontinuouszrneshwitha larger diameter gear .ljyhiohvisvslidingly supported on the tubularmember |88 ofthe torque responsive rnechanis'rn -,|,8 9,the`gear|93being connected by a pin l|94 witiraroslss sutiable the hollow b orej ofthe member |88. The radial facevof the hub of 'this gear |93, on theside adjacent the canlriling member |79 0,v ,is provided with cammingsurfaces |96; between which and the surfaces |9| are' proeduspaeed steelballs |91. The rod |95 is freely slilaplemtnmtne member las but islimited m this sliding movement by `the axial length of the slot il;vthe'melnber v |00 through which the pin |94`ext,ends` ,jlhereforethe4gear |93 and the 'Qainmingrsurfaces |9| are directly responsive tothetorqus Oith inputshff. 33- y tspringl 9S acts upon the rod |95 andnormally urges the latt/ervandethe attached cammingsur- .faees L90I onAgear |93 in a direction yforfprovid- Aing a,v driving relationship withthe surfaces |9| thmughthebells |91. The felice .f .thiespfine'issuchhoweven that whenlthe torque differentialbetyveen cthedtyvoYcamining members of the Y.torquernechanism |89, which, as explainedabove, `isrepresentative of the torque ldifferentialbeeenjheinput; andoutput shafts, exceeds a predetermined'value the camming surfaces |9|and |96 tend to move irumferentially with re- -specttoeah other thus`moving the rod I9?- and -thegear n| ,93; axially against the force ofthe spring 5,90 and-to thenleft l as shown in` Fig. 2A.Adjacent-thegrearaeerof the gear |93, thatis at the .left thereof asviewed` in Fig. 2A, ismountd a lever. lgmvvhicnis pivoted intermediateits ends and has onefnarrn bearing againstthe gear |93 "Whilethedotherarrn yis provided with an abutment portionadapted to engage the end of avalve bodyim of. theeovernor valve HB.. i

v; -I tvvil l. be evident from the eonstruation just V'described that,Whentheclutches and 50 are .disengaged and clutch 11| .is engaged, theshaft 95 then drives the spindle 32 through gears |92, jg?, thetorqueres'ponsive frnechani'sni |89, gears 431, |85, ist, 112,.elu'tchfm, gears et and its ges rotatie stp and gears lesen@ l It 'or-gears and, H2. Thisirn'parts a non-Working pr. crawl speed rto thespindle at vvhich speed 'gear iftingiofjth transmission perfected.shift- {tprtaevigffelfential between the 'input and Aurteilt entre .orthe, transmise@ .is @que to. Jr les than ia, predetermined value whenthe spindle is driven lat the 'said non-'working speed. This islachieved A(by virtue of the f act that when the said torqueJdiierelfltial excessive thergear |93 lnovesaxially ,y latterengages thevalve body 200 ofthe governor valve preventing shifting of the latter toheposition in which fluid under pressure is sup- .ld to the gearshifting fluid motors, as hereinvafter 'described in detail. However,when the 'torque 4dilerential between the input and output jshaift'softhe transmission has attained the said predetermined value, there is 'nolonger a circumferenti'al displacement between the two cannning"iiiel'n'bers of the torque responsive mechanisms@ i 'it at the `force.of Vthe spring |98 is sufhcient to iagain 'urgegthe gear 4'|93y toitsinitial position `as shown Ain fun linges. in Fig. jzA so` that thelever .ier

body has a pair ofspaced lands 20| 'and 202 lcated on either sideof;a('ratdial openingr the body which lc'oinniunieates with an axiallyextending b'ore 204 therethrough; ,'lhe 'righthand end of the valvebody, `as viewed Iin, Fig-A4, is closed byva sleeve-like plug mer'ilber205,. the hollow interior. of which is provided v/Jith a 'Howrestricting member 206.V This ov'v restricting member 206 may beforir'ied in substantially the same manner asthe flowrestricting xneibr|`5| previously described. l-Iowever, in the illustrated constructionthis nlenbeif is provided by threading it and the bore of the ine'rnber205 and then removing a portion of one of the threads to thus provide atortuous passageway between 'the members. Y n l n Pressured fluid isadapted to enter the valve |10 through a port 201.**Whieh'ciiimiinic'ates through a passagewayA 208 and anopening 209 in the plugmember 2.05 with the regioneat one side ofthe 'ow restricting meinber205s() that the'` uid under pressure is only gradually fapplied tothebore 20d of*` the valve body 200, The length and size o'f the .tortuousfpassageway through theflow restricting member 206v a'refs'o chosen thatthere is apredeterini'ned tirne. vdelay between the instant when thepressured' iiuidz'is appliedto the port 201 and .the time when the valvebody 20d isV ioved vtlfler'eb'y. against Ythe force of thecompressionspring V210th `its out- Wardinost position Aas represented infull. li'r'l'esfin Fig.. 2A.V YThis, tristement f the jvalvsbotry tnocausesthe land 2 02 -to uncover ,an pe'nihgin the Wall of the valve'corhmunicatio'rjl lwithvthe port 201 so that therpre'ssur'ed fluid inaythen by-pass the flow restriction 20Sr nel howow through the bore 204and the openingZO to la port 2H, see Fig.4,lthus Iallowingiuid underpressure to be.'supplied to the selector valve 'as hereinafterde'scribedinde'tail. When, however, the application o; uid. pressure to the port201 is terminated, or,y the lever |19r .is rocked as p'reviouslydescribed, y due. to. torque diiferenti'al f in excess V`of that'permissible for clutch, shifting, the valve body 20`0.is movedtoftheright to the position shown in Figs. 4 ai'id. This visalfso t theposition (lf-the valve when the `inachirie is idle ,and no pressureisfaplied to `the port .201, the .jvalvebodyqbeing.retained in 'thispesi'tion bythe spring v210.- A- drain for the portion 'lof thevalvephan'lbe'r .containing 'the 'spring 2 |0 `is provided through aport 5212. l

In addition to .the v reviously.. topera-Qting valvesof .the mechanism,van, inching. valve vis also provided to-perrnitaslotv rotationor'inchi'ng of the work spindle. This valve, which is generallydesignated 2|3,"is.mounted on the headstock. 26 adjacent the.. controlhandle. I6! fand comprises la vvalve housinv'gZlA, 'see Fig. 1(1,Ainwhich a valve body 2|5. is slidably. mountedwith `the outer end offthelatter providedfwith afsliitable knob. 215m. The valve body 2 I5 'isprovided '2776 normally urging the valve body -215 Yto itsoutermostpositionfasshownin-Fig i7.

A "seen vthat -pres'sured'fl'uidfrom the port 'f2 |f| of 'the housing ofthe selector and interlocking valves |39 and |43. The inlet passagewayin the valve housing connecting with this port 228 is controlled by aspring pressed check valve 229, see Fig. 15, which permits iiow of uidonly in the direction into the interlock and selector valves. Beyond thecheck valve 229 the inlet passageway in the valve housing connects withthe region in front of the flow restrictor and with a passageway 239extending through the valve housing and communicates with an annulargroove 23| in the selector valve body |3|. This groove 23| communicateswith the hollow interior of the valve body |3| through spaced openings232a and 232b, see Fig. 16. The groove 23| is also in communication witha passageway 233 in the valve body for a purpose hereinafter described.The interior of the valve body |3| also communicates with the exteriorthereof through a plurality of spaced openings 234, 235, 236 and 231arranged in axially spaced groups extending circumferentially above theperiphery of the valve body |3|, see Fig. 16. As shown therein, theholes or openings 234 are located at the 1st, 2nd, 3rd, 4th, 6th, 8th,10th and 12th circumferential positions of the valve body. The openings235 are located at the 6th, 8th, 10th, 12th, 13th, 14th, 15th and 16thcircumferential positions of the valve body |3|. The openings 236 arelocated in the 1st, 3rd, 5th, 6th, 9th, 10th, 13th and 15thcircumferential positions of the valve body; and, the openings 236 arelocated at the 3rd, 4th, 9th, .10th, 11th, 12th, 15th and 16thcircumferential positions of the valve body |3I.

The openings 234 are adapted to be selectively placed in communicationwith a passageway 238 of the valve |39, see Figs. 14 and 15, while theopenings 235, 236 and 231 are adapted to be placed in communication,respectively, with passageways 239, 249 and 24|. The passageway 249communicates with the port |21 in the cylinder ||9 of the fluid motorfor shifting the gears 64 and 85. The passageway 24| communicates withthe port |28 of the cylinder |29 of the fluid motor for shifting gears92 and 93. communicates with the port |28 in the cylinder |2| in thefluid motor for shifting the gears ||l| and |93 while the passageway 239communicates with the port |29 in cylinder ||1 of the fluid motor forshifting the gears |09 and ||9. The ports |23, |24 and |25 on theopposite side of `the pistons in these uid motors all communicate witheach other and with the port 242, see Fig. 18, in the cylinder |9 whichin turn communicates with the aforementioned passageway 233 of the valve|39.

The valve body |3| of the selector valve |39 is also provided withspaced .circumierentially extending grooves 243, 244 and 245. Thesegrooves cooperate with passageways 246, 241 and 248 respectively whichare all connected with the drain conduit 249 extending to a uidreservoir 259, see Fig. 18. As will be seen in Fig. 16, the grooves 244and 245 have axial extensions 25| and 252 at spaced circumferentialpositions of the valve to selectively communicate the passageways 238,239, 249 and 24| with the drain 249 at the circumferential positions ofthe valve at which such axial extensions align with the last-mentionedpassageways. Thus, in the rst position of the selector valve, indicatedby the numeral 1 at the left-hand side of Fig. 16; passageways 239 and24| are connected with the drain thus providing for( reliefA of lthepressured fluid fronlthe- Passageway 238 vcylinders H1 and 12u throughvune ports |29 and |26 respectively. These same cylinders and ports arelikewise connected to drain in the 2nd, 5th and '1th positions of theselector valve. Similarly, the passageway 239 and the associatedcylinder ||1 are connected to drain at the 3rd, 4th, 9th and 11thpositions of the valve, while the passageway 24| and cylinder |29communicating therewith are not then being drained. It will be similarlyseen that the cylinder |29 is'connected to drain through the passageway24| and grooves 252 in the 6th, 8th, 13th and 14th positions of thevalve as well as in the previously mentioned positions where both thiscylinder and the cylinder ||1 are so connected. Likewise, it will beseen that the cylinder ||9 will be connected to drain through thepassageway 249 and the groove245 in the 2nd, 4th, '7th, 8th, 11th, 12th,14th and 16th positions of the selector valve |3I. Also, the cylinder|2| will be connected to drain through the passageway 238 and the groove244 when the valve body |3| is in its 5th, '1th, 9th, 11th, 13th, 14th,15th or 16th positions.

Referring now to Figs. 10 and 11, it will be seen that the previouslymentioned slidable valve body |56 of the main control valve |52 has fourspaced lands, 253, 254, 255 and 256, for controlling the passage of uidthrough passageways 251, 259, 259, 269, 26|, 262 and 263 in the valvebody |55 as well as through the passageway 264 in the end cover plate|54a of the valve. The passageways 251, 258, 259 and 260 are connectedwith an axial bore, disposed at one side of the center of the valve body|55 and communicating with drain passages 265, which may be connected todrain conduit 249 or directly to the reservoir 25|).

The passageway 264 is connected to a conduit 266, see Fig. 18, whichextends to a passageway 261 through the bracket ||8 in which the gearshifting members 68, 89, |91 and ||6 are slidable. This passageway 261is controlled by radially extending passages through the said gearshifting members, there being two such passageways 268, 269 in eachmember and corresponding to the two extreme positions of those members.Consequently, the passageway 261 through the bracket IIB can provide forunobstructed now of fiuid only when the said radial passageways 268 or269 of the gear shifting members are aligned with the said passageway261. As will hereinafter be apparent, this construction insures that oneor the other offeach pair of shifting' gears will be in proper operativerelationship in the transmission before the gear shifting operation iscompleted and hence will be hereinafter referred to as an interlock.

The passageway 261 is connected to a conduit 210 which extends to a port21| of the time delay valve |43, see Fig. 14. As shown in that ligure,the port 21| is normally in communication with the space between thelands |46 and |41, the said space in turn being in communication with'the groove 244 of the selector valve |30 which groove, it will beremembered, communicates with the drain conduit 249. k n

Referring now tofFigs. 9, l1 and 18, it will be seen that the rotativevalve body |55, in addition to the aforementioned passages 251 to 263,has four circumferentially spaced axially extending recesses 212, 213,214 and 215, and a diametrically extending passageway 216. The recessesor grooves 212, 213, 214 and 215 are interconnected by an annular groove211 which communicates with the drain opening or Apassageway l265. The

diametrical passage 21E is adapted to be placed selectively incommunication `with passageways 218, 213 and 280, the Aopenings to whichare all disposed in the same axial plane. The passage- Way 218communicates through a conduit 28| with the passageway 64 of thecylinder or actuator gior the forward clutch 4B, `and the passage- Way219 communicates through a conduit 282 with the passageway 1-2 -fcr thecylinder or actuator for the reverse clutch 5B. The passageway 2.80communicates with the port 222 of the inchng valve 2|3, which port is incommunication with Vthe port 22| o f that valve in the normal ornon-operated position of the valve. -The port 22| communicates Ywith theport or passageway 8| for the brake actuator 1| through interconnectedpassageways or conduits 283 and 284.

The port or passageway A262 `of the -main control valve |52communicates', through a lpassageway 285 lWith the port 224 of theinching valve 2|-3. This port is normally in communication with thepor-t n223 when the inchi-ng valve is in normal position, SeeEig..1'7,and the latter port communicates, through a passageway or conduit285,-withthepassageway or port |281 Aof V the crawl clutch -|1f|. Thepassageway 2&5, which communicates ywith port `2|2 of vthe rmain valve4| -52,-als,o is in communication -With Va conduit 28-1 `which-is--connectedfwith-the port y2|l1 of the governor Avalve fand,fromtheport x2| of the governor v valve, the Aaforomentioned vconduitI221 Vextends tolthe'vinlet '228 of the preselectorvalvelil-andigtsassociated delay valve |43. The-inlet porti-,63 of themainvalve |52 -is oon-- -nected by -a fconduit 288-with-thesupply conduitJ28S-fandl the @latter is connected-with-the output of a pump 290, theinput side of-which iscon -neetedwiththereservoirzu. fillhe Ifluidpressure supply -conduit '12 asf-is; also connected with the V-valve 43through the :aforementioned 4conduit f' F50. Apressurqgauge 29|isalsofconnectedvvith -the vpressure supplyyr-conduit 289, through thepassageway #288 `and v-a passageway 1292. .This -gaugeis)preferablyf-locatedpn the-headstock 1.26 "adjacenttheman -control-val-vefhandle |16 i and the' knob-2 `Picfvfgantlfie inehing valve v2|13.

For convenience '.-in manufacturing assembly 'and'maintenanca --a numberof 'thaaforementionedfuid Apassageway/'S between the `.several valves`-areprovide'd in -theefforrn of grooves -or `fr ecesses' injcovering-or housingv platesratherfthan byseparatepipesgor conduits.'Such grooves. or vpassageways Vhave `been `indicated at various places1in V`the -`Vdra-wings, -see for example figs. i 9, "1;4'=and' 11.However, *'ior simplicity. andA .clarity Yof disclosure, certain oftheinterconnections between the variousvalves 4have been l`diagram--matical-ly representedin Fig. ltasthoughthey wereconduits or pipesratherl than suchgrocves f orpassageways. fMoreover, the inohing-valve.2 |3 Ahasheen'shovvnin sectional' view inlig. 18 and also indicated' in-hrokenA lines infrontviewin "the same' ligure -toI facilitate anunderstanding v oftheconnections-thereto. A- Consequently-- cer--Ltainfof theconnections to` thisvalve appear as .inftheir .genericSenseas Lrepliesenti.ne a. Ulfeans )for transmittingiiuid Vare intendedto cover a constructionin-which the. .connections trasf- "fectedithroughmilled grooves or islots in parts Vremainingat their illustratedpositions.

116 of the frame or cover plates of the apparatus, through separatepipes, or through combinations of such grooves and pipes.

It will also be undersligd .that in the schematic representation of thehydraulic circuit, certain of the drain conduits or passagewaysextending from various .of .the valves have been omitted for the sake ofclarity. Likewise, various conventional features, such .as .reliefvalves for maintaining a predetermined pressure inthe systeni, and otherWell-known expedients normally employed in `an apparatus of .thisnature, have not been here' illustrated.

4The operation .of Lthe eVlfLl Valves and other iiuid .pressure actuatedmechanisms will be h est understood from a brief description of themaniner in which the vapparatus is utilized in operation of a machinetool to eiect change of speed and/or 4'stopping of .the spindle. Let itbe assumed, that ptver is being supplied to the input shaft `33, -thatthe .gears ,of Athe transmission are positioned .as shown inEigs..f2A.aI1.d 2B, .that the fluid `pressure pump 29.0 is .inoperation, that a .workpiece is `rnoi'inted in the chuck on vthe workspindle 32, 4and that the handle LB! Aof the smain controlvalve `|52.is.in .positions I and N. C onsequently, the p assageways .218, 215| and280,1 eading to the .actuators .for theorward clutch ,48, the Areverseclutch .55! and Athebrake 1 3 are all connected to drain .through thegrooves Ior recesses 2.14, 215 and :2.1.3, respectively, see `Fig. All,withthe kresult that .the spindle .32 is stationary. -The selector valve.-432 willbe .in 1its 9th position,

.since this is .the setting Vorrespondiilg l with .the

positions of the gears illustrated in Figs. 2A,and r2B. Alsothe inchingvalve 2 |.3 and thegovernor valve |719 vvvillhe intheir normalpositionspas indicated in Fig. 17, and Figs. .4 .and 5, .respectively.

`Now let it beassumed that .thenext operation of the machine toolrequires that thespindle .p32

rotate ina.forward.directionlandat the speed produced .when the gear 8.2meshes with geard,

'gear92 meshes with gear, 94,.,gear-ii1-mesheswith gear if!! and `geariii! .meshes .with gear i2. Thiswillrequirethatthe gears |D|and ||l3 be-shiftedirom the position shown .in Fig. kZBto the other positionthereof .with .the other. gears .fThe new positions of `thegearsand.theirLshiters will thenbe asshown in. Fig..1.8.

`InYorder to condition the apparatusfor efectinglthis shifting, l.theoperator .sets the .selector vvalve |36- in: its. 3rd. position..which,asJseen,V from :F.ig. 16, will provide .communication from..the

interior .of the valve-shody |3|.through.openings 234, 2% and 231 to thepassageways,238, 24,8 and 24|, respectively,v and thencev to. .the ports|28, |21 fand 26, respectively.. of 1 the cylinders |2 ligand |28.`ingwith the port |2Softhecy1inder, |22willnow VUloeconnected by agroove.25| and the .groove-246, to the 4drain.4 conduit'ZS..Nopressured-iiuid hasx asyet been supplied` to'l cylinders.|.|9,.-,.|20 G5 The, .passageway .2739. communicatand -|V2|,-howeverjsincethe path for-the uid to-the 'interiorlofthe selectorvalve433 is now 7 blocledbythe movable.- member or plugjZllG, of thegov'ernorvalve |1. .A1so,'sincetheshiftable valve body lss'or the mainyaweispositioned as ,shown Yinflig. 19, theiiuid under pressure' at the inletport-'263 is prevented from communicating 1 with the crave port ze; byvoitue of' tneialnd 25s.

Y Sluit-.ing ofthe gears tothe positions indicated in FiIg'. 18 is 'now'initiated'-py the'operator shown in that figure.

17 position III. This shifts the valve body |55 t0 the position shown inFig. l0, the valve body being held in this position by spring detent|61.

This shifting of the valve body |55 new provides communication betweenthe inlet port 233 and the crawl port 252 of the main valve |52 so thatfluid under pressure is now supplied through the passageway 285 to theport 224, of the inching valve 2 I3. From thence, the fluid passesbetween lands 248 and 2 i9 and through the port 223 to the Conduit 285and through the latter to the passageways |8I, |80, |19 and |18 of thecrawl clutch |1I thereby applying fluid under pressure behind the pistonI'i'i so that the friction members of the clutch are engaged.

Consequently, a crawl speed is now imparted to the spindle 32 from theinput shaft 33 through the gears |92 and |93, the torque responsivemechanism |89, the gears |81, |05, |855 and |l2, the crawl clutch |1I tothe gear 94 which, being in mesh with gear H33, drives the shaft |02 andgears im and H2 thus rotating the spindle 32. 'Sincethe spindle wasinitially at rest there will be a torque differential between the inputshaft 33 andthe spindle 32 until such time as the speed of the spindlehas reached the proper crawl speed for gear shifting. Hence, the camsurfaces ISI and |95 of the torque responsive mechanism |83 will belcircurnferentially displaced with the result that the gear |93connected with the carri surfaces IEG, is shifted to the left as viewedin Fig. 2A moving the lever |33 to the position indicated in brokenlines, so that the valve body 200 of the governor valve is maintained atthe position shown in Figs. #i and 5. Therefore, although fluid underpressure has valso been supplied from the passageway v285 through theconduit 23| to the port 201 of the governor valve |15, this fluid canonly pass through the passageway 208 and the port 23e into the regionbetween the cap 205 and the flow restrictor 266. Hence, the fluid isonly gradually admitted to the interior 204 of the valve body 200 and nouid pressure can as yet pass through the port 2| When the spindle 32 hasreached its crawl speed so that there is no appreciable torquedifferential between the input and outputshafts of the transmission,there will no longer be a relative circumferential displacement betweenthe cam surfaces |9| and |35 so that the spring |08 restores thesemembers and the gear |33 to their positions as shown in Fig. 2A, thusallowing the lever |59 tomove to its full line position Hence, when thefluid pressure in the 'interior 204| of the valve body l2130 has reacheda value greater than the force eri(- erted by the spring 2|0, the valvebody 203 will be shifted to the left from its position shown in Figs.' 4and 5, thus bringing the opening 203 into communication with the port 2|The above mentioned shifting of the governor valve, as a result ofequalization of the torques between the input and output shafts, nowallows pressured fluid to be supplied from port 201 of that valve aroundthe flow restrictor B and through the bore 204 to the opening 203 whichis now aligned with the port 2| Hence, the pressured iiuid passesthrough the conduit 221 to 'the inlet 222 of the selector valve |30thereby unseating the check. valve 223 so that the pressured uid `is nowapplied through the passageway 230 to the groove 23| and from the latterthrough the ope-nings and 23227 into the interior of the valve body i3I. It will be remembered that this valve body |3| was initially set atits 3rd position so that pressured fluid is now supplied from the-interior of the valve body |3| through the openings 23d, 235 and 231aligned with the passageways 238, 240 and 24| while passageway 239 isconnected to drain. Consequently, iiuid under pressure is now suppliedthrough the ports |28, |21 and |25 of the cylinders I2|, H9 and |20.Fluid under pressure is also supplied to the left-hand sides of thecylinders H0, |20, |2| and |22 through the passageway 230, port 2132 andports |23, |24 and |25. However, the areas of the pistons available foraction of pressured duid thereagainst are smaller on the sides adjacentports |23, |22, |25 and 2M than on the sides adjacent the ports |26,|21, |23 and |20. Therefore, since the pistons B9, 38 and ||1 areinitially disposed at the positions shown in Fig. 18, only piston |08new moves and this movement is to the left as viewed in the drawings.Consequently, only the gears |0| and |03 are shifted so that the geari0! now engages gear |00 and gear |03 is disengaged from gear 91|, thisshifting being effected at rthe crawl speed thereby preventing clashingof the gears. The other gears remain in the relationships shown in Figs.2A and 2B.

Simultaneously, with the application of fluid under pressure to the gearshifting fluid motors, fluid under pressure is also supplied at the rearof the flow restricting time delay I5I in the interlocking valve |43.Due to the tortuous passage provided-for the liiuid through this iiowrestricting assembly, a predetermined time elapses before sumcientpressure is transmitted therethrough to shift the valve body from itsposition illustrated in Fig, 14, where itis held by the duid pressurefrom conduit acting upon the small diameter c nd of the extension |48 ofthe body |45. However, when a predetermined time interval has elapsed,suicient fluid will have passed through the flow restrictor I 5I so thatthe force exerted on the face of the land |46 exceeds the force exertedupon the reduced diamter portion |58 with the result that the valve body|45 is shifted to the left from its position shown in Fig. 14. rfhiscauses the land |46 to move sufficiently to uncover the openingcommunicating with the drain groove 244 and the land |41 movessufficiently :to place the port 21| in communication with thepassageways 230 through the groove 23 I. Consequently, fluid underpressure will no Vlonger be supplied at the right-hand sides of thepistons 89, 93 andr |08 but the fluid which has been supplied theretowill be retained by the check valve 223. v

In normal operation, the gear shifting rods 4or Ielements 38, 38, |01and I6 will have all reached their desired positions by the time thefluid pressure in valve |43 becomes great enough to shift the valve bodyand consequently the openings such as 258 or 263 will have aligned withthe opening 251 through the bracket member H8, thus indicating that thegears are either properly engaged or disengaged as the case may be.Therefore, a passage for fluid under pressure is now providedfrom thepassage 23|! of the selector valve through the groove 23| and betweenthe lands |46 and |41 of the valve |523 to the port 21|, thence throughthe aligned openings of the gear shifting elementsy and the bracketlltvto the conduit 258. The conduit 256 is connected with the passageway2515i communicating with the region to the right of the shiftable valvebody |53 of the main valve. Hence, the pressured iluid now acts on thevalve body |56 and shifts it 'to the left, from its position shown inFig. 10,

against the force of the detent- |61,` and to the position shown in Fig.19, the valve body being held in its new position by engagement of thedetent |61 in the right-hand groove |58, see Fig. 19. Therefore, thevalve actuating handle IBI is automatically returned to its I position.It will be observed that during the actual shifting of the gears atleast one of the openings such as 268 or 259 through one or more gearshifting elements or members will be out of alignment with respect tothe opening 251 in the bracket I I8, thus blocking application of fluidpressure to effect shifting of the valve body |55. When, however, allthe gears are properly positioned, the openings will align as mentionedabove thus returning the handle |6| to its position I and thereby advisethe operator that the gear shift has been properly completed.

The return of the valve body |56, as just mentioned, has moved the land255 thereof to a position between the ports 262 and 263, thus termiatingthe' application of fluid pressure to the crawl clutch |11 and thelatter is now connected to the drain through the port 252, the spacebetweenthe lands254 and 255, and the drain passageways 259, 265. Also,the application of uid under pressure to the governor valve |10 isterminated and this valve is likewise drained through the samepassageways as provide for drainage of the crawl clutch. As mentionedheretofore, the uid pressure which was applied to the gear shiftingfluid motors is not now released, however, since thisuid is trappedbythe check valve 229 thus maintaining the gears in their shiftedpositions. The removing of uid pressure from the governor valve I 1Ballows the spring 2| B to return the valve body 20B to its position asshown in Figs. ,4 and 5, thus preparing the mechanism ior furtherregulation of subsequent gear shifts under control of the torqueresponsive mechanism |83.

It Vwill be remembered that the assumed rotation of the spindle is to bein the forward direction'atthe selected speed for which the gears havejust been shifted. Therefore, the operator must now move the handle I6 Ifrom its neutral or N position, as shownv in Fig. 9i, to the forwardposition, indicated F in Fig. 18. In order to effect this movement theoperator pushes outwardly slightly on the' handle |51 moving the latterfrom its Position I to position II as indicated in Fig. 19, thusenabling the lug |52 to clear the lug |63, the spring pressed plunger|54 being depressed during this movement. The operator may now turn thehandle I to the forward position and when the'handle is thereafterreleased the plunger |64 returns the handle to its I position whilestill at the forward position.

Movement of the handle IGI to the F or forward position has rocked thevalve body |55 so as to place the passageway 216 in alignment with theport connected with the passageway 218. Therefore, uid under pressure isnow supplied from the inlet port 263 between the lands 255 and 256 ofthe valve body |56 to the passageway 218,

thence through conduit 28| to the passageway 84 which is incommunication with the bore SD and passageways 53 and 58 at the rear ofthe piston 56, so that the latter is moved to the left as viewed in Fig.2A. This eects engagement of the' friction members of the forward clutch49 so that the gear 4| is clutched with the shaft 43.

Consequently, the spindle 32 is now driven from the inputshaft 33through the gears 39, 4 I, 82, 84, 92, 94,130; IDI, IIB and |12.

function for which the mechanism has `been placed in operation has nowbeen comzileted` and the operator now wishes to stop the rotation of thespindle and of the change speed transmission. Since the handle |5| wasautomatically returned to its position I while at the F' or forwardposition, the operator now pulls outwardly on the handle IGI to move thelatter to position II and thereby clear the stop lug |63'whereupon thecontrol lever IGI may then be rocked laterally from position F toposition B which `corresponds with the braking position. This willrotate the valve body |55 so that the passageway 215 therethrough is nowmoved from alignment with the passageway 218, leading to the forwardclutch, and is placed in communication with the port whichV is connectedto the brake 13 through the inching valve 2 I3. The iiuid under pressurenow passes between the lands 2|1 and 2 I8 of the'valve 2|3 and entersthe brake cylinder or operator 13 behind the piston 19 thus moving thelatter'to engage the friction members of the brakeand apply a brakingforce to the shaft 13. Since the shaft 43 is a part of the transmission,the braking force is also applied to the spindle 32. 'The rotation ofthe valve body in moving the passageway 215 as just mentioned has alsoterminated application of fluid under pressure to the forward clutch andthe latter is now connected tothe drain through the conduit' 28| and agroove such as 211 of the valve body |55. After the spindle has come torest the operator may thenmove the control handle ISI to theneutralposition,l 'indicated N in Fig. 9, thus terminating theapplication of fluid under pressure to the brake and connesting thelatter to drain through a groove `such as 213 of the valve body |55.

Let it now be assumed that the next operational step in the machiningcycle is to be a lefthand threading operation at a lower speed, forexample, with the gear 82 meshing with gear 84, gear 93'meshing withgear 85, gear |90 meshing with gear IIiI, and gear IIB meshing with gear||2. This corresponds to the position 1'of the selector valve I`3I sincein this position openings 234 and 235 will be placed in communicationwith the ports |28 andv |21, respectively, of thefiuid motors |2| andII9. The operator may thus position the selector valve |3| eitherduringthe previous operating cycle or just prior to initiating thissecond step. When thus positioned, the selector valve |3I will beconditioned for supplying fluid under pressure to the uid motors orcylinders |2| and IIS at the right-hand sides of the pistons thereof, asviewed in Fig. 18, while the corresponding'sides of the pistons in themotors I|1 and |20 will be connected to drain through the grooves orrecesses 25| and 252 and the circumferential grooves 244 and 245communicating therewith.

Shifting of the gears, after the selector valve hasbeen thus set, isinitiated by the operator pushing inwardly onthe handle I6 I. This movesthe valve body |56 to the-right from its position asshown in Fig. 19 tothe position as shown in -Fig. 10. Hence, the lands'of the valve body|56 scribed. This shifting of the valve body |56 also terminates thesupply of iiuid under pressure to the-ports and connected passagewaysfor the forwarda'nd reverse clutches as well as to the brake even thoughthe handle |6| may not have been previously placed in the neutralposition N.

It will now be apparent that the spindle 32 is again connected with theinput shaft 33 through the crawl clutch |1| and, so long as the torqueof the shaft 33 is different from that of the spindle 32, the torqueresponsive mechanism prevents the valve body 200 of the governor valvefrom shifting to the position in which fluid under pressure is suppliedto the selector valve and to the gear shifting fluid motors. Fluid underpressure does, however, gradually enter the bore 204 of the governorvalve through the flow restricting portion 206 thereof so that, by thetime the torque relations of the input and output shafts of thetransmission are substantially equal thus moving the rlever |99 from itsposition restraining movement of the valve body 200, sufficient uidpressure will have been developed in the bore 204 to shift the valvebody 200 to a position supplying fluid under pressure through the bore204 and to the conduit 221 connected with the selector valve |30.

Therefore, fluid under pressure is now supplied through the passageway230 and the openings 234 and 236 of the selector valve to the Dassages238 and 249 which communicate with the fluid motors |2| and I I9 at theright-hand sides of the pistons thereof, as viewed in Fig. 18.Simultaneously, fluid under pressure is also supplied to the left-handsides of the pistons 89, 99, |08 and ||1 through the port 242 and theports I 23, |24 and |25. It will be observed, however, that the areas ofthe pistons against which fluid pressure can act on the left-hand sidesthereof, as viewed in Fig. 18, are less than the areas of these pistonsavailable for action of fluid pressure on the right-hand sides thereof.Consequently, while fluid under pressure is applied to both sides of thepistons 89 and |08, the latter do not move from their positions as shownin Fig. 18 since they are held by the greater force exerted by theright-hand sides thereof. However, no fluid under pressure is applied atthe right-hand sides of the pistons 98 and ||1 since the ports |26 and|29 are now connected to drain. Therefore, the piston 1 will remain atits righthand position as shown in Fig. 1S and piston 99 will move tothe right under the influence of the fluid under pressure appliedthrough the port |23 so that the gears 92 and 93 are shifted to engagethe latter gear with the gear 95.

Simultaneously with the application of fluid under pressure to thecylinders H9, |20, |2I and |22, uid under pressure is also appliedthrough the ilow restrictor 15| of the interlock valve |43. Therefore, apredetermined time after the gear shifting is initiated, the valve bodywill again be moved, as has been previously described, to place thepassageway 230 in communication with the port 21|, through the spacebetween the lands |46 and |41, thereby supplying fluid under pressure tothe conduit 210 of the interlock for the gear Shifters. Therefore, whenthe shifting of the gears is completed so that the passageways throughthe gear shifting elements are in alignment with the passageways 261through the bracket I8, fluid under pressure will be suppliedtherethrough to conduit 266 and passageway 264 thereby causing theshiftable valve body |56 to be returned to its initial position. Thisterminates the application of fluid under pressure to the crawl clutch,so that the latter is disengaged, and also returns the handle |6| to itsposition I in the manner which has been previously described therebyindicating to the operator that the gear shift is completed.

The operatoil then moves the control handle |6| outwardly, from positionI to position 1I, and laterally rocks the handle to the R positionthereby rocking the valve body |55 so that the inlet port 263 is nowplaced in communication with the passageway 219. Consequently, uid underpressure is now applied through the conduit 282 to the actuator for thereverse clutch 50 thereby engaging the frictional members of the clutchso that the gear 41 is now clutched to the shaft 43 thereby causing theinput shaft 33 to drive the transmission and spindle through the gears40, 44 and 41. The spindle is now rotating in the reverse direction andat the selected speed and will continued to so rotate so long as thehandle' I6 is left in this position.

If it be desired to stop the spindle at the end of the second operation,the handle |6| may be rocked laterally to the position marked B as hasbeen previously described, thereby rocking the valve body |55 so as toterminate the application of fluid under pressure to the reverse clutch50 and apply uid under pressure to the brake 13.

The second operative step in the assumed cycle has been described as aleft-hand threading operation at a lower spindle speed than the spindlespeed for the first step and with the spindle having been brought to astop before starting the second operative step. However, if the secondoperative step had required a different speed from the first step butwith the spindle rotating in the same direction, then it would not havebeen necessary to move the control handle |6| from the F (forward)position in order to obtain the new spindle speed. In such a case, theoperator could set the speed selector valve |30 to the desired spindlespeed for the second step of the machining cycle of operations while therst step was still in progress. Then, upon completion of the rst stepand while the spindle is still rotating at the speed for that step, theoperator would need merely to move the control handle inwardly fromposition I to position III while retaining the handle in its F position.This will shift the valve body |56 inwardly as previously described,thus terminating the application of fluid under pressure to the forwardclutch 49 and supply fluid under pressure to the crawl clutch |1 I.Since, however, the speed of the spindle 32 would then be greater thanthe crawl speed, there would be a torque differential between inputshaft 33 and the spindle 32 so that the torque responsive mechanism |89would prevent shifting of the governor valve body 200, as has beenpreviously described, until the torques of the input and output shaftsare substantially the same whereupon the shifting of the gears toprovide the preselected speed would automatically occur as will now beapparent` After the shifting of the gears is completed, the resultingalignment of the passageways, such as 261 or 268, through the gearshifting elements with the passageways 261 in the bracket |8 will againreturn the valve body |56 and the handle |6| to their initial positions.Since the handle |6| was left in its F (forward) position, uid underpressure will now again be applied to the forward clutch 49 and theapplication cf pressured uid to the crawl clutch is terminated so thatthe spindle 32 now begins rotation in the forward direction and at thenew speed. Any spindle speed may similarly be Dreselected and thenecessary shifting of the 4`gears effected while the main control handleis irl-either atel'y stopped.

23 the F (forward) or R (reverse) positions without necessitatingmovement of the control handle back to neutral 4position or to brakeposition between each such selection and shift.

The inching valve 2|3 is provided for the purpose of permittng anintermittent slow rotation or inching of the spindle. This inching is atthe crawl speed and is obtained by placing the main control lever ll inits B (brake) and I positions and then pushing on the knob 215e of thevalve 2|3 thereby moving the valve body 2 l 5 so that the land S isbetween the passageways 223 and 22e and the land 2|? is between thepassageways 22| ands222. Consequently, the fluid under pressure from theinlet passageway 253 of the main valve |52, and which passestherethrough and through port 26| to the passageway 2&9 due to thesetting of this valve |52, does not now pass to the brake actuator butis communicated through the inching valve, between the lands 2|? and2id, port or passageway 223 which is connected by the passageway orconduit 286 to the inlet for the actuator of the crawl clutch lll.Hence, the crawl clutch is engaged so that the spindle is now driven atthe crawl speed as will be apparent from the prior description.

Theinitial positioningr of the handle at the B (brake) position preventsfluid under pressure from being supplied to either the forward orreverse clutches i8 and 5%, so that inadvertent driving of the spindleat a speed other than the crawl speed is prevented. Furthermore, theoperation of the inchlng valve places the lands 2 le and 2lii thereof inthe position which connects the actuator for the brake I3 to the drainpassageway "i211 It will also be observed that the opera-tion of thevalve 223 moves the land 2|8 to a position interrupting communicationbetween the ports 224 and 233 of the inching valve. This is to preventsimultaneous inching and gear shifting. It will be further observedYthat the inching of the spindle cannot be inadvertently effected whilethe transmission is conditioned for driving the spindle in either theforward or reverse directions or when the handle iSl is at the neutral,N, position, since at these times the port 26| of the valve |52 isconnected to the drain so that no fluid under pressurecan be supplied tothe port 222 of the inching valve and thence to the crawl clutch. Ifdesired, a mechanical interlock may also be provided between the inchingvalve 2 i 3 and the main control valve 52 so that the valve body 2|5 ofthe inchingvalve cannot move inwardly when the valve body liS of themain valve |52 has been thus actuated, and conversely.

lnching of the spindle is terminated by simply releasing the pressurefrom the operating knob 2| 5a thereof whereupon the valve body 2| 3 Visrestored to its initial position shown in Fig. 17 by the spring 225.This interrupts the communication between the ports 222 and 223 thusterminating the application of fluid under pressure to the-crawl clutch.The port 222 is now restored to communication with the port 22|, throughthe space between the lands 21'! and 2|8, and hence the iiuid pressureapplied from the main valve |52 through the passageway 28B passesbetween the lands 2|? and 2id of the inching valve and is appliedthrough the passage or port 22| to the passageway or conduit 283 and 284connected with the actuator for the brake 13. Consequently, release ofthe knob 2|5a of the inching valve applies the brake to the transmissionand, since the spindle is rotating at its crawl speed, it is immeditothe operator.

fi, i

It will therefore beapparent that. thespindle 32 may be rotated slowlyat the. crawl speed by holding the inching valve in its operatedposition or the spindle may be intermittently rotated or inched adesired amount by repeated momentary actuations of the inching valve2|3. Thisfacilitates locating the spindle at a. desired circumferentialposition as, for example, in proper relation ship for cooperation with apower chuck wrench when a machined workpiece is to be removed from and anew workpiecegripped by the chuck. The inching or partial rotation ofthe spindle for this purpose may also be effected by hand when thecontrol handle IGI is in N (neutral). position, since at that time thebrake and the main clutches are released.

It will now be evident that,.in accordance with this invention, aplurality of speeds for a moving part of a machine tool may be providedthrough a transmission, the gears of which are automatically shifted toa preselected relationship when theV torques of the input and outputshafts are properly related for eiecting the shifting without clashingof the gears. Consequently, the operator need only actuate a selector todetermine the gear relationships desired and then operate a singlecontol lever when it is desired to initiate shifting of the gears toprovide the selected relationship. Therefore, the selection of a desiredspeed of the spindle for the next machining operation may be made whilethe machine is performing the next preceding operation and the selectedspeed relationship is not established until required by the Furthermore,it is not necessary for the operator to bring the spindle to rest beforeinitiating a change of speed since he may actuate the` main controllever for initiating the. gear shifting cycle even though the speed ofthe spindie is not at that time such as to be proper for the shifting-This will not result in injury to the mechanism because the shifting isunder theautomatic control of a torque responsive deviceso that theactual shifting of the gears `does not occur until the .torquerelationships of the input and output shafts are proper. This insuresthat the` shifting of the gears will always be effected under the properconditions without the necessity of the: operating exercising anyjudgment With respect to those conditions. Consequently, the possibilityof damaging the transmission by improper shifting is eliminated.Moreover, machining operations are facilitated by the'reduc tion of .thenumber of movements required of the machine operator and by thereduction ofthe timey required for changing speeds of the spindle tosubstantially the minimum theoretically permissible value.

Although a preferred embodiment of the invention has been illustratedand described in considerable detail, it will be understood that theinvention is susceptible of various adaptations and modifications.Consequently, the invention is not to be considered as limited to thestructural details herein illustrated and described except as requiredby the spirit and scope of the appended claims.

Having thus described the invention, I claim:

l. In a. machine tool having a movable part, a transmission for movingsaid part at dierent rates including input and output shafts andshiftable elements providing selected speeds of said output shaftrelative to the input shaft, power operated means for effecting shiftingof said shifable elements, settable selector means adapted toselectively connect a sourceof power to said means for shifting saidelements,v and means to control the application of power to said poweroperated means including a portion movable in response to the torquedifferential between said input and output shafts to selectively permitor prevent application of power to said power operated means throughsaid selector means so that shifting of said shiftable elements inaccordance with the setting of said selector means is prevented untilthe torque of the output shaft bears a predetermined relationship to thetorque of said input shaft.

2. In a machine tool having a movable part, a transmission for movingsaid part at different rates including input and output shafts andshiftable elements providing selected speeds of said output shaftrelative to the input shaft, power operated means for effecting shiftingof said shiftable elements, settable selector means adapted toselectively connect a source of power to said means for shifting saidelements, and means operatively connected with said input and outputshafts and including a movable member controlled by the torquedifferential between said input and output shafts and positionable toselectively permit or prevent application of power to said poweroperated means through said selector means, whereby shifting of saidshiftable elements in accordance with the setting of said selector meansis prevented until the torque of the output shaft bears a predeterminedrelationship to the torque of said input shaft.

3. In a machine tool having a movable part, a transmission for movingsaid part at different rates including input and output shafts andshiftable gears providing selected speeds of said output shaft relativeto the input shaft, power operated means for effecting shifting of saidgears, settable selector means adapted to selectively connect a sourceof power to said means for shifting said gears, means to control theapplication of power to said power operated means including a portionmovable from a position in which application of power to said poweroperated means through said selector means is prevented to a position inwhich the said application of power is permitted, and means responsiveto the torque differential between said input and output shafts forgoverning movement of said portion, whereby shifting of said gears inaccordance with the setting of said selector means is prevented untilthe torque of the output shaft bears a predetermined relationship te thetorque of said input shaft.

4. The combination as defined in claim 3 and further comprising meansnormally urging said movable portion to the position thereof in which itprevents application of power from said source to said power operatedmeans, and means for applying a force to said movable portion to effectmovement thereof to its other position, the said means for governingmovement of said movable portion being operative to prevent movementthereof in response to said force until the turques of said shafts bearthe said predetermined relationship.

5. The combination as defined in claim 4 and further comprising timedelay means associated with said movable portion to prevent movementthereof until a predetermined time after the said force is directedthereagainst.

6. The combination as defined in claim 3 wherein the said transmissionfurther comprises a pair of clutches adapted to be selectively operatedto effect rotation of said output shaft in either the forward or reversedirections, and a single manually operable control lever operable tocontrol the application of power to said power operated means throughsaid selector means and to selectively actuate the said clutches.

7. The combination as defined in claim 6 wherein the said transmissionfurther comprises a brake means and means operative in response toactuation of said control lever to one position thereof to actuate saidbrake means.

8. In a machine tool having a movable part, a transmission for movingsaid part at different rates including input and output shafts andshiftable gears providing selected speeds of said output shaft relativeto the input shaft, means in said transmission including a poweroperated clutch for imparting a slow non-working speed to said outputshaft, power operated means for effecting shifting of said gears,settable selector means adapted to selectively connect a source of powerto said means for shifting said gears, manually operable control meansselectively operable to apply power to said clutch and to said gearshifting means in accordance with the setting of said selector means,and means to control the application of power connected intermediatesaid control means and said selector means and including a portionoperatively connected with said input and output shafts for movement inresponse to the torque differential between said shafts to selectivelypermit or prevent application of power to said gear shifting meansthrough said selector means, whereby actuation of said control meansfirst imparts a non-working speed to said output shaft andthereafter'effects shifting Aof said gears after the torque of theoutput shaft attains a predetermined relationship to the torque of saidinput shaft.

9. The combination as defined in claim 8 and further comprising meansresponsive to shifting of said gears in accordance with the setting ofsaid selector means to terminate operation of said clutch and therebyterminate the application of vsaid non-working speed to said outputshaft.

l0. The combination as defined in claim 8 and wherein the saidtransmission further comprises a pair of clutches adapted to beselectively operated to effect rotation of said output shaft in eitherthe forward or reverse directions, and the said control means comprisesa single member operatively connected to control the application ofpower to said power operated means through said selector means and toselectively control actuation of the said clutches.

1l. The combination as defined in claim 10 and wherein said transmissionfurther comprises a brake means and means operative in response toactuation of said control member to one position thereof to actuate saidbrake.

12. The combination as defined in claim 11 and further comprising amember manually movable to simultaneously release said brake means andapply power for actuating the said clutch which imparts the slownon-working speed to the output shaft to thereby effect inching of theoutput shaft and of the said movable part connected therewith.

13. In a machine tool having a movable part. a transmission for movingsaid part at different rates including input and output shafts andshiftable elements providing selected speeds of said output shaftrelative to the input shaft, fiuid pressure actuated means for shiftingsaid shiftable elements, a source of fluid under presl 27 Y sure,settable selector valve means operatively connected to said source ofuid under` pressure and to said fluid pressure actuated means toselectively direct fiuid under pressure to the latter, valve meanshaving a portion movable to selectively permit or prevent application offluid under pressure to said fluid pressure actuated means as determinedby the setting of said selector valve means, and meansoperatively-connected to said input and output shafts for movement inresponse to the torque differential therebetween to control movement ofsaid portion of the last-'mentioned valve means, whereby shifting of thesaid' shif'table elements in accordance `with thev setting of saidselector valve 'means is prevented until the torque of the output shaftbears a predetermined relationship to the torque of said input shaft.

14j In a machine tool having a movable part, a transmission for movingsaid part -at different rates including input and output shafts and-shiftable elements providing selected speeds of said output shaftrelative to the input shaft, fiuid pressure actuated means for shiftingsaid shiftable elements, a source of fluid under pressure, selectorvalve means settable to selectively "direct the application of fluidunder pressure to Asaid fluid pressure actuated-means, main valvefineans for selectively directing .iiuid under presrsure from=saidsourc'etosaid selector valve for effecting shifting-of said-shiftableelements in accordance with the' setting of said selector valve,

Va'governorv valve connected intermediate the said sele'ctor andmain-valve means andl having -a portion "movable to selectively-permitor prevent ap- 'plicationof fiuid f under r pressure to said fluidpressure actuated means, andv means operatively connected to saidinputf-and output shafts for .movement inr response to the torqueVdifferential 'therebetween to control movement of said porltion'of the:governor valve, whereby shifting of the saidshiftable 'elements isprevented until the 'torque ofthe ouput shaft bears a predeterminedrelationship to the torque of said 'input shaft.

S 15. The `com'bin'ationas defined in claim 14 la-ndfurthercomprising'means vautomatically inwterposing a time delay between theactuation -of'said main valve andi-movementof the said portion of the*governor valve tothe position th'eieof which permits-applicationofiiuid under fpressure' to said selector valve.

Y 5.16. In a'machinetool having a movable part,

Ya tran'smissionvfor `'moving said part atl different rates includinginputand output shafts yand ushift'a'ble gearsproviding-selected speedsof said output shaft relative to the input shaft, fluid pressurevactuated means for shifting said gears. afsource of .fluid un'olerrpressure, selector valve means settable to'scl'ect the application ofuid .underpressure to'said fluid Vpressure actuated wmeans, main valvemeans for selectively direct- Jing fluid under pressure from said sourceto said i selector valvefor effecting-shifting of said gearsiii-accordance with the setting of said selector valve means, agovernorV valve connected intermediate'the-'saidselector and maur-valvemeans and having a portion movable to selectively per- -mit or preventcommunication 'Y between s said fselecto'rvalve means and said mainvalve means. and vmeans including a= portion vmovable in revspouse tothe torquefdifferential between .said `input iand'output'shafts andpositioned for coop- "eration with the saidmovable portion ofAthegovernorfvalve to control-the movement Ithereof,

whereby shifting of the gears of the transmission YA,28 v can beeffected only when thetorque of thesoutput shaft of the transmission isin predetermined relationship t the torque of said input shaft.

17. In a machine tool` having a mcvablepart, a transmission-formovingsaid partat diiferent rates including input and output shafts andshiftable elements providingA selected speeds of said loutput shaftlrelative to the input shaft, means in saidtransmission including a iiuidpressure operated clutch for imparting a slow nonworking speed to saidoutput shaft, fluid pressure actuated means for shifting said shiftableelements, selector valve means settable to selectively direct fluidunder pressure to said uid pressure actuated means, a source of iiuidunder pressure, main valve means for controlling the application of nuidunder pressure from said source to said clutch and to said selectorvalve means, a governor valve having a portion movable to'selectivelypermit or prevent communication between said selector valve meansvandlsaid main valve means, and means operatively connected to said inputand output shafts 'formovement inv response tothe torque differentialtherebetween to control movement ofisaid portion of the governor-valve,iwhereby actuation of said main 'valvrst imparts a non-workingspeed to said output shaft and thereafterl'eiiects shifting ofthe'said'sliift- .ableelernents when the torqueY of the, output. 3Gshaft is'substantially the same as'that of said input shaft.

18. In a machine toolvhaving a movable 4part. a tranmission 'formovingsaiclfp'art atv different rates ,including input 'and' outputshafts v4and zshiftable elements providingV4 selected `speedsof saidoutput Vshaft"relai-,ive to the V` input shaft, .means in saidtransmission inciudingauid pressure operated'clutch 'formparting a slownonworlring speed" to `'said output shaft,- iiuidpres- 40'sure actuatedmeansfor "shifting saidshiftable elementa'selector'valve means settableto fselectively direct fluid 4under pressure to said fiuid pressure'actuatedmeans Aa source of fluid 4under pressure; main valve meansconnected t'ocontlol LL-application ofnuid under `pressuri-i to vsaidclutch Ameans/and to said selector valve means, agevernor valveconnected'- intermediate i said `main valve and said selector valve 'andhaving -a portion movableV to selectively permit `or`lzireventfc'omi'munic'ation between s'aid I'selector valve means"and'said main valve means, means operatively v4connected to said inputfand iutput shaftsfor *movement in response` to the' torque'differential therebetween to controldmovement'of saidportion` ofthegovernor valvefand v'means movable l in response" to application' ofuid: underipressure tosaidselector valve means to Acause a. Epor- -Stionof saidxmainvalveemeans' to move to fa ip'osition `terminating thesupply of .fluid runder' presossure to'saidclutch, whereby :actuationoff' said @main valve rstf imparts a :non-working -speedtosaidoutput'shaft'then effects shifting of the said shiftableel'ementswhenthe torque ofthefoutput I shaft is substantially the same asrthat ofsaidin- (i5-put shaft, and thereafter fterminatesthefnon working speedof said output shaft.

19. Thecombination as defined in claim 18:and further comprisingmanually .operable valve 'means Vconnected between said source of fiuid7o underpressure andsaidclutchto controle-application of iiuidunderpressureftothe latterfor .inching saidmovablepart at? thesaidnon-work- `ing speed without'effecting-shifting of saidshifti able:elements.

20. In a machine tool having a movable part,

